1. Field of the Invention
The present invention relates to a method of and an apparatus for editing information recorded on a magnetic tape in a unitary editing machine or the like.
2. Description of the Related Art
Heretofore, it has been customary in broadcasting stations to edit materials to be broadcast and record the edited materials on video tape cassettes. For example, a plurality of commercials (CMs) are edited and recorded on one video tape cassette, producing a single CM tape. According to an editing process for broadcasting, materials to be used for a program are edited and recorded on a video tape cassette.
Video tape cassettes on which original materials are recorded are usually called material tapes or the like. A video tape cassette as a material tape is played back on a video tape recorder (VTR) to reproduce a signal, and the reproduced signal is processed into a material signal that is recorded on a broadcasting video tape cassette which will be played back for broadcasting.
One conventional editing system will be described below with reference to FIG. 1 of the accompanying drawings.
As shown in FIG. 1, a video tape cassette 301 as a material tape is set in and played back by a playback VTR 302. A broadcasting video tape cassette 313 is set in a recording VTR 308 for recording an output signal from a video special effect adder/audio mixer 307. If a simple broadcasting tape is to be produced, then the video special effect adder/audio mixer 307 may be replaced with an editing machine, and may be dispensed with and the playback VTR 302 and the recording VTR 308 may be directly connected to each other.
The editing system shown in FIG. 1 operates as follows: The video tape cassette 301 as a material tape is played back by the playback VTR 302 to reproduce a signal, and a special effect is added to the reproduced signal. The reproduced signal with the special effect is supplied to the recording VTR 308, and recorded on the broadcasting video tape cassette 313 that is set in the recording VTR 308.
The playback VTR 302 has a playback head 303 connected to a fixed contact 305a of a head selector switch 305 and a playback head 304 connected to another fixed contact 305b of the head selector switch 305. The head selector switch 305 has a movable contact 305c that can selectively be connected to the fixed contacts 305a, 305b by a switching signal supplied from a system controller (not shown) in a main VTR unit 306 of the playback VTR 302.
The video special effect adder/audio mixer 307 adds various special effects including a mosaic effect, a moving effect, a reducing effect, an enlarging effect, a rotating effect, etc. to a video signal from the playback VTR 302, and applies a process such as mixing to an audio signal from the playback VTR 302. An output signal from the video special effect adder/audio mixer 307 is supplied to the recording VTR 308. The supplied signal is subjected to analog or digital signal processing for signal recording in a main VTR unit 312 of the recording VTR 308. The processed signal is then recorded on the video tape cassette 313 that is set in the recording VTR 308.
The recording VTR 308 has a recording head 309 connected to a fixed contact 311a of a head selector switch 311 and a recording head 310 connected to another fixed contact 311b of the head selector switch 311. The head selector switch 311 has a movable contact 311c that can selectively be connected to the fixed contacts 311a, 311b by a switching signal supplied from a system controller (not shown) in a main VTR unit 312 of the recording VTR 303.
There is known an editing technique called an "A/B-roll" in which two images (A-roll and B-roll) reproduced respectively by two playback machines are freely moved therebetween through a two-image combining process such as mixing, wiping or the like. If the editing system shown in FIG. 1 is to carry out such an A/B-roll editing procedure, then another playback VTR in addition to the playback VTR 302 needs to be connected to the video special effect adder/audio mixer 307. Video and audio signals reproduced as an A-roll by the playback VTR 302 and video and audio signals reproduced as a B-roll by the added playback VTR are processed by the video special effect adder/audio mixer 307, and the processed video and audio signals are recorded on a video tape cassette set in the recording VTR 308.
There has been proposed an editing apparatus which has an improved editing efficiency and is made convenient to use by displaying first and second points in a certain unit of image data on a display means, indicating image data of the displayed first and second points with an indicating means, and displaying the time code data of the indicated image data of the first and second image data, and the status and identification number of a related device. For example, an editable unit of image data displayed on a screen can be deleted, copied, moved, or exchanged in position by a pointing device or a keyboard thereby to modify the contents of edit files EDL1.about.EDLn. Since an editing process can be effected without cumbersome procedures as of playing back video tape cassettes on a plurality of VTRs to recheck the image data and confirming and entering storage addresses with a keyboard, the efficiency of the editing process is improved. For further details, reference should be made to Japanese laid-open patent publication No. 6-302157.
As described above, the A/B-roll editing process to be performed by the conventional editing system requires two playback VTRs, i.e., a VTR for playing back an A-roll and a VTR for playing back a B-roll.
In the editing system shown in FIG. 1, the playback VTR 302 may be used as a VTR for playing back an A-roll, and a newly added playback VTR may be used as a VTR for playing back a B-roll. If a process carried out by the video special effect adder/audio mixer 307 needs to be redone in such a system configuration, then it is necessary to operate the playback VTR 302 again to move the playback position of the magnetic tape in the video tape cassette set in the playback VTR 302 to the beginning of the material as the A-roll, and also to operate the added playback VTR again to move the playback position of the magnetic tape in the video tape cassette set in the added playback VTR to the beginning of the material as the B-roll. Thereafter, the playback VTR 302 and the added playback VTR are operated in a playback mode, and reproduced video and audio signals as the A and B-rolls need to be processed by the video special effect adder/audio mixer 307.
Stated otherwise, if an editing process is to be redone or rehearsed, i.e., practiced prior to a real editing process, in an editing system using VTRs, then it is necessary to operate the VTRs to move the playback positions of magnetic tapes to the beginnings of materials, and to wait until the VTRs move the playback positions of magnetic tapes to the beginnings of materials. Such an operating procedure and a waiting time are necessitated because the playback and recording devices are VTRs. As a result, it is highly difficult to achieve an improved editing efficiency with an editing system using VTRs. There has been a demand in the art for an editing system with an improved editing efficiency.
Another problem with the editing system shown in FIG. 1 is that once cables are connected based on given signal paths, playback and recording VTRs are uniquely determined. Since the playback VTR 302 shown in FIG. 1 is preset as a playback VTR, if the playback and recording VTRs are to be switched around, then it is necessary for the operator to disconnect cords from output terminals of the recording VTR 308 and the playback VTR 302, connect the output terminals of the recording VTR 308 to input terminals of the video special effect adder/audio mixer 307, and connect input terminals of the playback VTR 302 to output terminals of the video special effect adder/audio mixer 307, provided that the playback VTR 302 is capable of recording information and the recording VTR 308 is capable of playing back recorded information.
Therefore, once the devices are connected in the editing system shown in FIG. 1, input and output paths for video and audio data to be edited are uniquely determined, and the determined input and output paths in the editing system or the manner in which the devices are used cannot easily be changed.
If the editing system shown in FIG. 1 is modified in order to alleviate the various shortcomings described above, then it is difficult to attain compatibility with the existing devices, e.g., compatibility such as of timing, data format, etc. between the exiting devices and another device which is to be incorporated in the modified editing system.